Filed of the Invention
This invention relates to a communication apparatus and a communication system for supporting safe traveling of a vehicle, and more particularly, to a vehicle traveling support communication apparatus and communication system for detecting another vehicle and a pedestrian as an obstacle and providing information to a vehicle driver.
Description of the Related Art
Various proposals have been made as a traveling support system for enabling a vehicle such as an automobile to travel safely. For example, vehicles communicate information with one another using a communication apparatus mounted on each vehicle (hereafter, referred to as a vehicle-to-vehicle communication) to exchange their own position information, and, if a collision between the vehicles is predicted, to provide information to an occupant in advance, or support the traveling such as operating a braking device. Further, a support system is proposed by which, in addition to providing vehicle position information, in order to prevent another vehicle from colliding with the occupant who got off the vehicle, when the occupant gets off, information is provided to the other vehicle by regarding the occupant as an obstacle existing around the vehicle to avoid an accident that the other vehicle collides with the pedestrian (for example, Patent Document 1). What is proposed in Patent Document 1 is that a sensor mounted on the vehicle where the driver got off detects the driver immediately after getting off the vehicle as a moving object around the vehicle, and provides the position information on the detected object through a vehicle-to-vehicle communication, allowing a driver of a surrounding vehicle to grasp not only the vehicle of interest, but also the presence of an obstacle around the vehicle in advance.
Moreover, it is proposed that in addition to a vehicle-mounted terminal device, a pedestrian carries a portable terminal device for transmitting position information, such that information is communicated between the vehicle and the pedestrian (hereinafter referred to as a pedestrian-to-vehicle communication), so as to avoid a collision between the vehicle and the pedestrian, and further, when a pedestrian carrying a portable terminal device is riding in a vehicle, information is not provided because the collision with the pedestrian is incorrect (for example, Patent Document 2). What is proposed in the Patent Document 2 is that whether a person carrying a portable terminal device is riding in the vehicle or outside the vehicle is determined based on the relationship between the position information on the portable terminal device and the position information on the vehicle, and whether to provide information on a collision is determined.
[Patent Document 1] JP-A-2009-282713
[Patent Document 2] JP-A-2005-009933
As described above, as a communication device and communication system for supporting safe traveling of a vehicle, much information is transmitted to provide a variety of information. However, as in Patent Document 1, in a situation where a vehicle-mounted sensor functions to transmit information on an obstacle therearound, for example, after a driver gets off the vehicle, even when the driver moves outside the detection area of the vehicle-mounted sensor, or even when an environmental condition gets worse while the driver is leaving the vehicle and the detection performance of the sensor is reduced, the communication should be continued in order to provide information. In addition, because, in a parking area and the like, many objects to be detected exist therearound and the sensor tries to transmit their position information, the transmission capacity is constrained, and in some cases, the sensor falls into a communication disabled state.
Moreover, as in Patent Document 2, in a situation where the position information on the driver after getting off the vehicle is provided by using the portable terminal device, when the driver is within the vehicle, information from the portable terminal device is restricted, but when the driver leaves the vehicle, the stopping vehicle and the portable terminal device continue to transmit information. Therefore, both of the side which receives information and the side which transmits information handle a lot of information, thus, problems such as the delay of response, communication disability, and the occurrence of abnormal operation may arise.
The present invention was made in order to solve these problems, and it is an object of the present invention to provide a smooth vehicle traveling support communication system by limiting the provision of information by determining, depending on the situation, whether to stop transmitting each position information transmitted by a vehicle-to-vehicle communication between a vehicle of interest and a surrounding vehicle and each position information transmitted by a pedestrian-to-vehicle communication between a portable terminal device carried by a pedestrian and a surrounding vehicle.